SCIENCE FILE | Science in Brief

One gene, a racer; two genes, a dud

A gene that helps control muscle development makes all the difference between an elite racing dog and a freak that is put down at birth, scientists reported in the Public Library of Science journal PLoS Genetics.

Racing whippets that carried one copy of the mutated gene were among the fastest runners, but those that carried two copies became unattractively bulky and were usually destroyed by breeders, the researchers said.

The gene is the blueprint for a muscle protein called myostatin. They found the mutation in 12 of 41 dogs graded A or B racers, and in just one of the 43 dogs in the slowest racing grades.